/*
 *  Copyright (C) 2006 Apple Inc.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public License
 *  along with this library; see the file COPYING.LIB.  If not, write to
 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 *
 */

#ifndef WTF_GetPtr_h
#define WTF_GetPtr_h

#include <memory>

namespace WTF {

    enum HashTableDeletedValueType {
        HashTableDeletedValue
    };
    enum HashTableEmptyValueType {
        HashTableEmptyValue
    };

    template<typename T>
    inline T *getPtr(T *p) { return p; }

    template<typename T>
    struct IsSmartPtr {
        static const bool value = false;
    };

    template<typename T, bool isSmartPtr>
    struct GetPtrHelperBase;

    template<typename T>
    struct GetPtrHelperBase<T, false /* isSmartPtr */> {
        typedef T *PtrType;

        static T *getPtr(T &p) { return std::addressof(p); }
    };

    template<typename T>
    struct GetPtrHelperBase<T, true /* isSmartPtr */> {
        typedef typename T::PtrType PtrType;

        static PtrType getPtr(const T &p) { return p.get(); }
    };

    template<typename T>
    struct GetPtrHelper : GetPtrHelperBase<T, IsSmartPtr<T>::value> {
    };

    template<typename T>
    inline typename GetPtrHelper<T>::PtrType getPtr(T &p) {
        return GetPtrHelper<T>::getPtr(p);
    }

    template<typename T>
    inline typename GetPtrHelper<T>::PtrType getPtr(const T &p) {
        return GetPtrHelper<T>::getPtr(p);
    }

// Explicit specialization for C++ standard library types.

    template<typename T, typename Deleter>
    struct IsSmartPtr<std::unique_ptr<T, Deleter>> {
        static const bool value = true;
    };

    template<typename T, typename Deleter>
    struct GetPtrHelper<std::unique_ptr<T, Deleter>> {
        typedef T *PtrType;

        static T *getPtr(const std::unique_ptr<T, Deleter> &p) { return p.get(); }
    };

} // namespace WTF

#endif // WTF_GetPtr_h
